OPPORTUNITIES AND CHALLENGES OF ELECTROCHROMIC PHENOMENA IN TRANSITION-METAL OXIDES

During the past two decades, electrochromic phenomena in transition metal oxides have been very widely studied. This unique phenomenon of electrically induced reversible coloration and charge storage in thin films has diverse applications that range from information display to neural networking in optical computation. Electrochromic devices using metal oxides can be classified into two broad categories (1) all-solid-state systems, and (2) semi-solid systems involving wet electrolytes. The principles underlying the operation of both systems appear quite similar, but there remain both scientific and technological issues that are poorly understood. In this paper we briefly discuss some of the opportunities and challenges for the application of electrochromic phenomena in transition metal oxides.